A force sensor apparatus, operatively mounted in a surgical instrument includes the force transducer. The force transducer includes a transducer body having a coefficient of thermal expansion, and at least one optic fiber, fixedly attached to the transducer body, including a Bragg grating and having a coefficient of thermal expansion matched to the coefficient of thermal expansion of the transducer body to mitigate polarization and calibration drift effects on the force transducer. The transducer body comprises a metal transducer body, and the metal transducer body is selected from a group of metal bodies including an aluminum alloy transducer body, a stainless steel alloy transducer body, a maraging steel alloy transducer body, and a titanium alloy transducer body. The at least one optic fiber comprises an optic fiber having a negative thermo-optic coefficient, such as a phosphate glass optic fiber reducing the thermal sensitivity of the transducer.
